The 7778 is part of Channel Master's high-performance Titan 2™ series of mast-mounted preamplifiers. Its low-noise, medium-gain design can solve a number of reception problems, and is especially effective for long-range "deep-fringe" applications used in combination with Channel Master's 4228 antenna. (See our article on Choosing & Installing an HDTV Antenna.)
Two-piece mast-mounted preamplifiers have an advantage over more typical one-piece in-line units because the amplifier module is mounted near the antenna itself, to eliminate amplification of any noise or interference in your coax cable. A preamplifier can improve reception whether the problem is weak signal strength at your antenna, or loss of signal quality due to a long cable run between your antenna and TV.
Installation is simple: run a length of RG-6 cable from your antenna to the 7778's amplifier module, and another RG-6 cable from the amp to the 7778's power supply. Power is provided to the amplifier via the RG-6 cable, so no other wiring is necessary, and the power supply can be placed indoors to avoid exposure to the elements. Finally, run a length of RG-6 from the power supply either directly to your TV, or to a video distribution hub.